When I first met them, before their baby boy was born, I could see their excitement, could hear in their voices a sort of nervous delight about what was waiting for them as parents. Just the idea of him was enough to make her giggle, make him wrap his arms around her and lean down to kiss the bump.

But there is something so definite about the change in atmosphere when you photograph them all together as a family. The little boy is even more beautiful than they could have imagined. A warmth has settled in their hearts, as he settles in their arms, yawning and smiling and falling asleep.

I spent the morning with them, through him being wide awake, to sleepy, to napping in the nursery, to being held, to waking, to smiling and laughing and fixing me with a look of such sweet curiosity that you could only say he has an old soul.

I don’t know how, but I’ve managed to stagger through 33 years of life without ever watching “It’s A Wonderful Life.” Until this Christmas Eve, that is. And now I’m smitten with it. So if somehow this beautiful film has passed you by, do something about it. It’s a fantastic reminder that the ordinary life filled with love, friends, and family is never a poor one.

Inspired by that, I’m going to celebrate one family in particular – how I meet them before they became 3, the joy of watching their little family grow, the pleasure of capturing that connection again and again. Their family story started with a maternity session in Battersea Park, where we dodged the threat of rain and avoided the eager flying formations of city seagulls. On a cool, overcast day we managed to find the colour of sunshine in the middle of all that grey.

London seems to attract the best people from around the world to make it their home. It also brings the friendliest, those that smile the widest, carrying the cutest bumps. I love to look back at the time before their baby son arrived, how they spoke to him, tickled him before they could see him, kissed his head before they knew the colour of his hair.

Pop back tomorrow to meet the baby boy that made their family complete.